Water treating apparatus



s. B. APPLEBAUM WATER TREATING APPARATUS Filed Sept. 14, 1937 2 Sheets-Sheet l Nov. 7, 1939. s, B, APPLEBAUM 2,179,246

WATER TREATING APPARATUS R W N N .g\ m 5 ENE; W K

Patented Nov. 7, 1939 PATENT OFFICE WATER TREATING APPARATUS Samuel B. Applebaum, New York, N. Y., assimor to The Permutit Company, New York, N. Y., 3. corporation of Delaware Application September 14, 1937, Serial No. 163,843

'8 Claims.

This invention or discovery relates to water treating apparatus: and it comprises an upright hollow cylinder adapted to carry a flow of water and having inlet and outlet means at opposite ends thereof, means for introducing a floc-iorming or precipitate-forming reagent near the inlet, a high speed agitator rotating in a horizontal plane adjacent the inlet end of the cylinder to impart a turbulent swirl to the flow of water and reagent, a relatively slowly rotating agitator in the cylinder arranged to impart to the liquid a slow agitfiion subsequent to the high speed mixing, substantially vertical rotating shafts extending above the top of the cylinder and arranged for driving the two agitators, and means for rotating the shafts, horizontal vane members usually being provided adjacent the outlet end of the cylinder for arresting the rotary motion of the liquid; all as more fully hereinafter set forth and as claimed.

The amount of any impurity in ordinary water is usually extremely small on a percentage basis. It is usually reckoned in parts per million or milligrams per liter. In purification, soluble im-' purities are rendered insoluble by adding a reagent, and after the reaction the treated water is turbid. The amount of chemical requiredin purifying water is also small, and in all cases there is the problem of distributing a rather small minor volume of chemicals throughout a large major amount of water with evenness and uniformity. Many chemicals are used in treating water. For softening water by removing lime and magnesia it is common practice to use a soda lime treatment. With muddy or turbid waters containing suspended mechanical impurities, it is common to use a coagulant which may be alum, ferric salts, etc. Whatever the way of purifying water adopted, the result is a small amount of solid matter evenly distributed through a large volume of water. Due to the slowness of the reactions at cold temperatures, the precipitates formed constitute a turbid suspension of particles of colloid fineness which are slow in settling. Precipitation and settling is accelerated by controlled agitation. There is no particular difliculty in securing an even admixture of a small volume of chemical with a large volume of water, but there is often difliculty and delay in subsequently forming, collecting and removing the fine solids. Settling is slow and large apparatus is required. For example in the ordinary soda lime treatment of water in the cold there is a fine first precipitate not altogether easy to settle and separate and an after-separation of solids which are still more diflicult of removal. It is common practice to store the treated water in settling tanks for a half day or more, and also to filter the stored water.

Various mechanical means have been devised 5 to hasten formation and separation of the solid matter giving turbidity to purified water. Such means have involved mechanical difliculties complicated by driving machinery under water.

In the present invention I provide a simple and 10 compact apparatus for treating water with reagents producing a precipitate or a 1100, in which a reagent is mixed with the water and admixture completed under conditions of violent swirling agitation. The mixture is then subjected to 15 a relatively slow and gentle agitation of such character as to expedite formation of readily-, settling particles. The second agitation is carried out under regulated conditions so as to be neither too violent nor too mild; there being an an optimum degree of agitation for maximum effect in settling the 1100. The object is to stir out the solids instead of stirring them in. My apparatus is so arranged that these rather complex agitations are produced by mechanism the vital parts 25 of which are protected from the water, and the zones of agitation are connected to each other ,in a way ensuring maximum emciency.

In the accompanying drawings are shown more or less diagrammatically, various modifications 30 of treating and flocculating apparatus within the purview oi my invention. In this showing Fig. 1 is a' view in vertical section of a downward flow fiocculating unit within a settling tank;

Fig. 2 is a horizontal section along the line 22 35 of Fig. 1;

Fig. 3 shows a modification of the agitator of Fig. 2;

Fig. '4 is a horizontal section along the line 4-4 of Fig. 1; 4

Fig. 5 is a horizontal section along the line 5--5 of Fig. 1; i

Fig. 61s a modified downward flow flocculating unit shown in vertical section within a settling tank; 45 Fig. '7 is a view in perspective of the spider of Figs. 1 and 6; and

Fig. 8 is a showing in vertical section of an upward flow fiocculating unit delivering into a separate settling tank.

Referring to the drawings, a flocculating unit may be disposed in a settling tank, as shown in Figs. 1 and 6; or it may be connected to a settling tank as shown in Fig. 8. The flocculating unit of Fig. 1, comprises a cylindrical tank-dike memher In having an open top and arranged inside a tank l2. An inlet pipe l3 delivers to cylinder III the fluid to be treated and a pipe H2 delivers a desired reagent solution. In the upper portion of the member l0 adjacent the inlet is a high speed agitator l4 having horizontal blades l5 and a vertical hollow shaft l6 passing through a collar l1 suitably mounted on a plate H which is supported by two beams 20 at the top of the apparatus.

motor l9 supported on plate H. Between the blades l5, stationary horizontal bailles 22 are attached to the cylindrical wall of the member In. These baffles serve when blades l5 are rotated to create a swirling movement in the liquid passing downwardly through the member ID.

Below the agitator-baiile system I4, 22, is a second agitator 23 comprising, as shown, top and bottom cross members 24 and 25 rigidly connected to a drive shaft 21 and vertically arranged blades 26 attached to the top and bottom members, and inclined with respect thereto as shown in Fig. 2. This driving shaft passes through the hollow shaft l6 of agitator I4 and is driven by motor 28 with integral gear reduction which is mounted upon a supporting structure 29, this being in turn mounted on the supporting beams 20. The inclined blades 26, rotating as indicated by the arrow in Fig. 2, move the fluid being agitated toward the center and thus eliminate a more or less stagnant core of fluid near the shaft 21 which would be agitated less than the fluid nearer the periphery. In a modified agitator shown in Fig. 3 the blades on one side of the axis are inclined in the opposite direction to the blades on the other side. Upon rotation in the direction of the arrow one set of blades moves the liquid toward the center whereas the other set moves the liquid away from the center, thus setting up a rotating horizontal current passing through the center. The agitator per se having oppositely inclined blades, as illustrated in Fig. 3, is not my invention and is specifically claimed in a co-pending application of Eric Pick, Ser. No. 264,922, filed March 30, 1939.

As shown, an outlet distributor 30 is arranged in the tank l2 surrounding flocculating unit ID. This outlet distributor has perforations I30 for collecting liquid, and delivers to a pipe 3| passing out through the wall of tank l2. As shown, the outlet distributor and collector 30 is arranged on the overflow principle, so that the level of liquid in the apparatus is kept at a desired height.

The flocculating unit is supported upon the bottom of the settling tank by a spider 33 carrying a guide bearing 34 in which shaft 21 rotates. This spider has stationary vanes 36 so that liquid flowing past the agitator 23 and having a horizontal rotatory movement contacts vanes 35 and the rotatory movement is arrested. The flow is straightened, in order to avoid interference with the settling in tank l2 outside the flocculating unit due to turbulence.

In operation, the agitator I4 is rotated at rela tively high speed and the agitator 23 at relatively low speed. An advantageous rotational speed is a peripheral velocity of about 300 feet per minute for the high speed mixing agitator and a peripheral speed of about 50 to feet per minute for the slow motion agitator. Liquid and chemical entering the flocculating unit through inlets I3 and I 12 are given a violent horizontal swirl for a period of from two to seven minutes by agitator l4 whereby they are thoroughly mixed. This is succeeded by a slower Gearing l8 connects the shaft to a rotation for a period of from twenty minutes to one hour by agitator 23 whereby precipitates of relatively large particle size are caused to form. The slow rotation is, by reason of the length of the vertical blades 26, greater in duration than the high speed turbulent rotation. Liquid leaves the flocculating unit at the bottom, and fiocs formed in the unit settle as a sludge in the bottom of the settling tank l2, and may be drawn off through an outlet pipe system shown as central pipe 40 and transverse perforated pipes 4|. Clarified liquid is withdrawn from the top of the settling tank through pipe 3|.

In Fig. 6 is shown a modified form of downflow fiocculating unit in which the high speed agitator is a vane propeller H4, directly driven at a speed of about 500 to 2000 R. P. M. by a motor l9 mounted upon plate I I on top of the cylinder H0, with an operating shaft 2| entirely independent of shaft 21 of the low speed agitator 23. A horizontal bafile 45 is arranged in proximity to the propeller H4, the baffle being supported upon a perforated plate 46. A second perforated plate 41 is arranged below the plate 46, and stationary vanes 48 between the perforated plates reduce the turbulent horizontal swirl in the liquid imparted by the propeller H4, working against the baffle 45.- With this arrangement the violent currents produced by propeller H4 are kept from reaching the region of the slow motion agitator. The well, mixed homogenized liquid passes through the perforated plates to the slow motion horizontal agitator having inclined blades as shown in Figs. 2 or 3 and thence through the bottom of the flocculating unit into the settling tank where the fiocs settle out.

In Fig. 7 is shown the construction of the spider 33 with vanes 36 and guide bearing 34 for the low speed agitator shaft.

In Fig. 8 the flocculating unit 2H1 is provided with bottom inlets 5! for liquid and H2 for reagent solution, and top outlet 52 delivering into a settling tank 54. The high speed turbulent agitator M4 is near the bottom of the unit, and is provided with horizontal blades H5 and horizontal baffles 222. The low speed agitator 223 is similar to that shown in Fig. 1. In this case shaft 245 of the high speed agitator passes through the hollow shaft 221 of the low speed agitator, and is, as shown, directly driven by the motor 28. Gearing 10 connects the shaft 221 with the operating motor I9. In operation, the liquid entering through inlet 5| and the reagent entering through pipe H2 are given a turbulent horizontal swirl, succeeded by a slow motion horizontal rotatory movement produced by inclined blades as shown in Figs. 2 or 3, causing accumulation of the solids into flocs. After passing the slow speed agitator the liquid encounters vanes 236, which break up the rotatory movement. The liquid carrying flocculated sludge passes out through outlet pipe 52 into the settling tank 54, comprising, as shown, cylinder 55 into which the liquid and sludge is delivered by pipe 52. Sludge settled from the liquid is drawn off through a valved outlet distributor 56. The clarified liquid leaves the settling tank near the top through pipe 51.

The unit as described, with a continuous verticalflow of turbid water, effects flocculation of the finely divided precipitates, and delivers a sludge-carrying liquid that is readily clarified by settling. If an exceptionally pure liquid is desired the settled liquid may be further purified by filtration. I claim: 1. Water treating apparatus for continuous flocculation comprising a settling chamber, a cylindrical upright member, liquid inlet and out let means at opposite ends of said member directing a vertical flow therethrough of liquid carrying impurities to be flocculated, the outlet means communicating with the settling chamber, means foradding a reagent to the liquiden'tering through saidinlet means, high speed agitator means adjacent the inlet end of the member for imparting speedy horizontal rotary motion to the flowing liquid with agitation and homogenization thereof, relatively slow motion horizontal rotary agitator means in a sue ceeding relation to said high speed means, two vertical shafts for driving said agitator means and means for respectively rotating said shafts "at different speeds and mounted above said member.

2. Flocculating apparatus comprising a settling tank, an upright hollow member disposed 25 within the settling tank and open at its lower end, means for introducing liquid to be treated and chemical into said member near its upper end, high speed agitating means located eccentrically in the upper portion ofsaid member, a r

30 substantially vertical drive shaft for said high speed agitating means, low speed agitating means located in the lower portion of said memher, a vertical drive shaft for said low speed agitating means, means for rotating both said 35 shafts, and outlet means for withdrawing settled liquid from the upper portion of the settling tank.

3. Flocculating apparatus comprising a flocculating chamber, means for introducing liquid to 40 be treated and chemical into said chamber near its bottom, high speed agitating means located in the lower portion of said chamber, a vertical shaft for said high speed agitating means, low speed agitating means located in the upper portlon of said chamber, a vertical shaft for said low speed agitating means, means for rotatingboth said shafts, a settling tank, a passage for conducting liquid from the upper portion 01 the flocculating chamber to the lower portion of the settling tank, and outlet means for withdrawing settled liquid from the settling tank.

4. In the apparatus of claim 1, bafile means arranged between the high speed agitator means and the low speed agitator means.

5. Flocculating apparatus comprising a settling tank, an upright cylindrical member disposed in the settling tank and through which liquid to be purified flows vertically downward, a high speed agitator depending from the top of the cylindrical member giving the entering liquid a swirling horizontal motion in its downward flow, a low speed'agitator also dependent irom the cylinder top and having vertical blades horizontally rotated giving the swirling liquid passing from the high speed agitator a slow horizontal rotatory motion in its downward flow, means for rotating the high speed and low speed agitators, the liquid passing from the low speed agitator into the settling tank, for separation of flocculated sludge.

6. Apparatus according to claim 5, wherein the cylindrical member below the slow motion agitator is provided with stationary horizontal vanes straightening the vertical flow or the liquid.

7. Apparatus according to claim 5, the low speed agitator comprising cross members supported at different levels, and the vertical blades being attached to said cross members at an cal blades attached to the cross members on one side 01. the center at an oblique angle to the cross members, and other vertical blades attached to said cross members on the other sideof the center at an oblique angle inclined in the opposite direction to the first mentioned angle.

emon. B. 

